SEOUL, South Korea — North Korea has likely supplied several types of missiles to Russia to support its war in Ukraine, along with its widely reported shipments of ammunition and shells, South Korea’s military said Thursday.

In a background briefing for local journalists, South Korea’s military said that North Korea is suspected of sending an unspecified number of short-range ballistic missiles, anti-tank missiles and portable anti-air missiles to Russia, in addition to rifles, rocket launchers, mortars and shells.

The contents of the briefing were shared with The Associated Press.

North Korea has been pushing to expand cooperation with Russia and China in the face of protracted security tensions with the United States and pandemic-caused domestic hardships. In an apparent sign of its economic troubles, the country is moving to close some of its overseas diplomatic missions.

Last week, South Korea, the U.S. and Japan strongly condemned North Korea’s alleged supplying of munitions and military equipment to Russia, saying such weapons shipments sharply increased the human toll of Russia’s war in Ukraine. Any weapons trade with North Korea would be a violation of multiple U.N. Security Council resolutions that Russia, a permanent U.N. Security Council member, previously endorsed.

Both Russia and North Korea dismissed the weapons shipment accusations as baseless.

Outside speculation about North Korean arms shipments flared after North Korean leader Kim Jong Un traveled to Russia in September to meet President Vladimir Putin and visit key military facilities. The U.S. and its allies accused North Korea of seeking high-tech Russian technologies to modernize its arsenal of nuclear weapons and missiles in return for its shipments of conventional arms.

In a private briefing with lawmakers Wednesday, the National Intelligence Service — South Korea’s main spy agency — said that more than a million North Korean artillery shells have been sent to Russia since August via ships and transport planes. The NIS said the deliveries roughly amounted to two months’ worth of shells for the Russians, according to lawmaker Yoo Sang-bum, who attended the NIS briefing.

The NIS assessed that North Korea has been operating its munitions factories at full capacity to meet Russian munition demands and has also been mobilizing residents to increase production.

The NIS said North Korea, for its part, is likely receiving Russian technological assistance over its plan to launch its first military spy satellite into space. North Korea’s two recent attempts to launch a spy satellite ended in failure due to technical issues. The North failed to follow through with its vow to make a third launch attempt in October, without giving any reasons.

South Korea’s military said North Korea also seeks to receive nuclear-related technologies, fighter jets or related aircraft equipment and assistance on the establishment of anti-air defense networks from Russia.

North Korea is currently focusing on enlarging its nuclear arsenal while refusing to return to talks with the U.S. and South Korea. The country’s economy is reeling from major setbacks caused by draconian curbs imposed during the coronavirus pandemic and stringent U.S.-led sanctions.

South Korea’s Foreign Ministry said Thursday that it confirmed North Korea’s plan to close its embassies in Uganda, Angola and Spain and a consulate in Hong Kong. The Foreign Ministry said North Korea may close additional diplomatic missions.

North Korean state media said earlier this week that its ambassadors to Angola and Uganda paid “farewell” visits to those countries’ leaders last week.

South Korea’s Unification Ministry said Tuesday that the closures reflect North Korea’s financial difficulties. It said the country has diplomatic relations with more than 150 countries but operates just around 50 diplomatic posts abroad.

The NIS said North Korea is preparing to expand its economic cooperation with China, its biggest trading partner and economic pipeline, before pushing to fully reopen its international borders. The NIS said it obtained intelligence indicating that North Korea sent an economic delegation to China last month to attract investors.